Process of and apparatus for treatment of precious metals



(No Model.)

E. J. FRASER.

PROCESS 0F AND APPARATUS POR TREATMENT 0E PRECIOSMETALS. No. 543,546. Patented July'. 30, 1895.

UNITEDASTATRS PATENT Grrlcn.

EDWIN J. FRASER, or 'SAN FRANCISCO, CALIFORNIA.

PROCESS F AND APPARATUS FOR TREATMENT OF PRECIOUS METALS.

SPECIFICATION forming part of Letters Patent No. 543,546, dated July 30, 1895. Application filed November 25.1893. sain No. 492,010. (Nomaden A To all wiz/ om it may concern.-

Be it known that .1, EDWIN J. FRASER, a citizen of the United States, residing at Sau Francisco, in the county of San Francisco and State of- California, have invented certain new and useful Improvements in Processes of and Apparatus for the Treatment ofPrecious Metals; and I do hereby declare that the following is a full, clear, and exact description thereof.

My invention relates generallyto metallurgical processes for separating the precious metals, and 'more particularly to such processes when employed for separating gold or other precious metal from a solution containing it.

The object of the invention is the recovery of the gold held in solution by co-operating voltaic, chemical, and mechanical means, whereby the mechanical action of the filtering elements is aided and supplemented by the local action -of a voltaic pile of vbattery elements, which themselves form the filter. The action .of the filter is thusv partly mechanical and partly voltaic and chemical, and

the result obtained is a quicker as well as a more complete separation of the gold from ,the

' solution.

My invention includes a process for treating the solution in the way above indicated, and also apparatus for carrying out the process, all fully hereinafter described, and shown in the accompanying drawings, in whichlxigure l is a vertical section of a filter constructed in accordance with my invention. Fig. 2' is a horizontal section upon the line o: x.

In describing my process Iassume that the gold has been separated from Jthe, ore by means of any desired solvent, and is held. in a liquid solution ready for subsequent treatment to, separate it from'the liquid.

I have shown in the drawings an apparatus for carrying ont my process, -in which A is a vessel of cylindrical or any desired shape, and having closed top and bottoni, into which lead inlet and discharge pipes l and 2. In the drawings the inlet-pipe is supposed to be at the top and the outlet at the bottom; but this, arrangement may be reversed, if desired, and the current caused to ilow upward or horizontally. TVithin this cylinder are placed the alternating elements of avoltaie pile, their number being proportioned to the size and capacity of the tank or vessel. I have shown a series of nine of each element in the drawings. The positive elements shown are plates of zinc 3, perforated with numerous holes, and lined upon both surfaces with sheets 4, of cloth or other suitable porous material. Alternating with the zinc sheets and filling the spaces between them are fillings of carbon 5 such as pulverized charcoal-which form the negative elements. To complete the circuit I usually connect the two ends of the voltaic pile by means of a stout insulated wirev 8, placed either inside or, as shown, outside the containing-vessel. I prefer to leave a space 6 at the inlet end in order that the solution, as it is admitted, may be spread and distributedover the surface of the rst disk.

The solution itself should be slightly acidnlated to make it an electrolyte,and thus produce a local voltaic action.

The eect of this is to decompose the solution and to precipil or hood 7, to prevent the charcoal from being washed into the outlet-passage. Now it will be seen that by this construction I use each of the two elements ofthe pile-to accomplish two different results. cipitant of the gold and the charcoal asa mechanical lter; but in addition both form voltaic elements, which, in connection with the electrolyte solution,- set up a local voltaic action the effect of which is to increase the speed of precipitation by decomposing the solution.

It should be mentioned that a zinc sponge can be employed instead of a plate, in order to give a greater surface or body 'of zinc.

The gold can be separated from the zinc in various Ways, such as by Washingor by simply scraping it off, and from the charcoal by subjecting the latter to heat sufficient to consume it.

l. The process of separating gold or other' precious metal held in an electrolytic solution, which consists in 'passingfthe solution through a vessel containing alternating por- The zinc acts asa pre-` TOO ous layers of zinc and carbon, to set upl local voltaic action, by precipitation, and by me- 1o voltaic action which tends to decompose the chanical flteringubstautially as setl forth.

solution, precipitating the gold in the carbon In testimony whereof I h ave axed my sigby filtration, substantially as set forth. nature, in presence of two witnesses, this'lOtli 5 2. Avoltaic and mechanical lter composed day of November, 1893.

'0f perforated zinc plates alternating with EDWIN J. FRASER.

porous llings of carbon, adapted t-o receive Witnesses: all electrolytic solution containing gold, and L. M. SEELY, toseparate the gold from the solution by local WM. F. HALL. 

